Blind-stitch felling machine



y 1942- c. w. MUELLER BLINDSTITCH FELLING MACHINE Filed Dec. 16, 1939INVENTOR. CHARLES W MUELLER ATTORNEY.

Patented July 7, 1942 BLIND-STITCH FELLING MACHINE Charles W. Mueller,St. Louis, Mo., assignor to Lewis Invisible Stitch Machine Company, acorporation of Maine Application December 16, 1939, Serial No. 309,519

12 Claims.

The invention herein disclosed relates to blind stitch sewing machines,and more particularly to blind stitch felling machines of the type thatare especially adapted for felling a superimposed layer of material upona base layer, such, for example, as a lining to a base fabric.

Machines of this type are disclosed, for example, in United StatesLetters Patents Nos. 1,739,080 and 1,740,901 issued respectivelyDecember and 24, 1929. In such machines, there is provided awork-presenting mechanism that includes a node-former arranged andoperated to form a node of the base material and to present the node forpenetration by the needle. As constructed prior to the invention hereindisclosed, the node-former of the work-presenting mechanism of suchmachines acts upon the fabric being sewn with a constant force. Inconsequence, if the node-former be adjusted to take care of the heavierwork on a job, such, for example, as two or more thicknesses of thematerial, it will on a single thickness of the material crush orcompress the material such that a deeper penetration than that desiredis effected. Such a condition exists in felling a lining to a coat inwhich flaps are provided for the pockets. If the force on thenode-former is adjusted to secure the desired penetration when thepocket flap passes between the work support and the presser foot, itmust be readjusted after the pocket flap is passed for the same forceacting on a single layer of material would compress the material and thepocket would be sewn shut.

By the invention herein disclosed there is provided work-presentingmechanism in machines of this type that compensates for variations inthe amount or thickness of the material passing between the work supportand the presser foot. In accordance with the invention thework-presenting mechanism of a machine of this type includes anode-former arranged and constructed to move toward the path of theneedle to a greater or lesser extent in accordancewith the resistance ofthe material between the work support and the presser foot. In onespecific arrangement of work-presenting mechanism constructed inaccordance with the invention, the node-former normally acts with aforce sufiicient to compress, without crushing, a single layer of thematerial but insufficient to compress several layers. When severallayers are presented, the node-former, upon engaging the work retractsto the extent of the effective additional thickness of material and thenacts with a force augmented to that necessary to form the node in theseveral layers of material. In this way the travel of the node-formertowards the path of the needle is decreased in accordance with theeifectiveness of the additional thickness of material and a uniformpenetration of the base layer is attained.

Work-presenting mechanism embodying the invention and suitable for ablind-stitch sewing machine having stitch-forming mechanism and meansfor actuating work-presenting mechanism is illustrated in theaccompanying drawing in which:

Fig. 1 is a fragmentary end elevation of part of a blind-stitch sewingmachine with the Workpresenting mechanism arranged thereon; and

Fig. 2 is a side elevation of the work-presenting mechanism with partbroken away to show the internal construction.

The work-presenting mechanism disclosed in the drawing is such that itmay replace the work-presenting mechanism of either of the machinesdisclosed in the aforementioned Patents Nos. 1,739,080 and 1,740,901.Because of this fact only the main presser foot I, the needle bar 2, theneedle 3 and a part of the work clamp 4 of the sewing machine have beenillustrated. These several parts serve to illustrate the position of thework-presenting mechanism in the machine and its relation to thestitch-forming mechanism.

Blind-stitch sewing machines of the type illustrated in theaforementioned patents include stitch-forming mechanism, work-presentingmechanism and operating mechanism for actuating the stitch-formingmechanism and for actuating the work-presenting mechanism in timedrelation with the stitch-forming mechanism. The stitch-forming mechanismincludes a needle, such as the needle 3, that is oscillated on one sideof the presser foot I and. the work-presenting mechanism operates on theother side of the presser foot to project nodes of the material throughan opening in the presser foot and present such nodes to the needle. Thework-presenting mechanism is actuated in timed relation with the needleand commonly through an oscillating shaft connected to the main shaft ofthe machine.

The particular work-presenting mechanism illustrated in the drawingincludes a block or carrier 5 that is slidably mounted, in the usualmanner, in the end of the work arm or work foot. The common actuatingmeans for the work-presenting mechanism, such, for example, as thatdisclosed in the aforesaid patents may be used to reciprocate thecarrier. The carrier includes a cylinder 6 in which a node-former l isslidably mounted.

This node-former, which directly contacts the work, forms the nodetherein and projects the node through the opening in the presser footfor presentation to the needle, is shaped, at the work-contacting end 8thereof and provided with an anvil 8a, as illustrated. The body of thenodeformer is circular in cross-section and makes a sliding fit withinthe cylinder 6. A keyway 9 formed in the body of the node-former andengaging a key Ill formed on the end of the cylinder 6 prevents thenode-former from rotating within the cylinder. A reduced extension llformed on the end of the body of the node-former projects through thebottom of the cylinder. This extension is threaded for a considerableportion of its length and a stop-nut l2 and check-nut l3 are threaded onthe end thereof. The stop-nut engaging the lower end of the cylinderforms an adjustable stop to limit the movement of the node-former withrespect to the cylinder and towards the presser foot or the path of theneedle. A spring I i within the cylinder acts between the end of thebody of the node-former and the bottom of the cylinder in a direction tourge the node-former towards the path of the needle. The spring l4normally exerts a force on the nodeformer of approximately two andone-half pounds. This force is normally sufficient to effeet, in lightwork, such as a single thickness of material, a node in the material andpresent the node to the needle.

For heavier work, such as, for example, when the flap of a pocket passesbetween the work clamp and the presser foot, a force materially greaterthan the two and one-half pounds of the spring I l is required topresent the work in the form of a node to the needle. To provide thisforce when it is required and in the proper relation to effectuate theintended purpose, as for example, in the proper relation to maintain thedesired penetration, there is provided additional yieldable meansarranged to act upon the nodeformer upon compression of the spring It.This additional yieldable means is mounted in a cylinder I5 secured tothe carrier 5 through a bracket l6.

Within the cylinder lethere is slidably mounted a plunger I! that issecured against rotation with respect to the cylinder by a pin 18secured in the cylinder and engaging in a longitudinal keywayl9 formedin the plunger. The cylinder l5, and in consequence the plunger H, isaxially alined with the node-former. The end of the plunger, adjacentthe protruding end of the extension of the node-former, is recessed toreceive the end of the extension II. The diameter of the recess is,however, of such size that the end of the plunger engages the check-nut53 upon compression of the spring I l.

The plunger I 7 has a reduced extension 2B that extends through thelower end of the cylinder l5. The end portion of this extension isthreaded. The lower portion of the cylinder I5 is internally threadedand receives the threaded end of a plug 2| through which the extension29 extends in sliding engagement. A spring 22 within the cylinder [-5acts between the end of theplug 2 I: and the plunger H in a direction tourge the plunger toward the node-former. For cer- 28 and a check-nut 29.

tain purposes, such as in felling lining to coats, this spring 22 actswith a force of approximately seven to eight pounds for light materialand with a greater force for heavier material. The force of the springmay be varied through adjustment of the plug 21.

For the purpose of adjusting the force of the spring 22, there isprovided a boss 23 having a knurled edge it. The boss 23 is boredlongitudinally and receives the plug 2i. Diametrically opposite slots 25are provided in the boss 23 and engage wings 2%; formed on the plug.Thus, while the plug isslidable in the boss it is caused to rotate withthe boss. By turning the boss, the plug through its threaded connectionwith the cylinder is moved longitudinally of the cylinder and socompresses or permits expansion of the spring 22.

The boss 23 abuts at one end against a knurled nut 2? threaded on theextension 26 of the plunger i! and at the other end against the end ofthe cylinder Hi, The nut 22? is provided for adjustably positioning theplunger ll with respect to the check-nut E3 on the node former. Throughthe nut 27 the gap between the check-nut l3 and the plunger i l, or theamount the spring It must compress before the plunger ll engages thenodeformer, may be adjusted for the particular work to be sewn; A springdetent 28 engages the knurled edge of the nut so that accurateadjustment of the gap may be attained.

The threaded end of the extension 29 of the plunger l'l extends throughthe nut 2?. On the extension, beyond the-nut 2-7, there is a stop-nutThe stop-nut 28 is provided to adjustably limit the possible movement ofthe plunger ll towards the node-former. Normally this stop-nut ispositioned such that the plungers movement toward the node-former islimited to contact with the check-nut it.

The plunger operates in conjunction with a rigid. adjustable crown 33which controls the depth of penetration of the needle. Such crowns arewell known in the art. The particular crown illustrated is formed on theend of a lever 3| that is pivotally secured to the side of the presserfoot by a machine screw 32. The position of the crown (ill, 1. e. itselevation with respect to the path of the needle may be adjusted by aset screw 33 threaded in the presser foot and having a knurled head 3s.A detent 35 is provided and cooperates with the knurled head foraccurate adjustment of the screw 33. The end of the screw 33 engages thecrown and limits its movement towards the path of the needle. Since theplunger, through the anvil, acts against the crown, the crown controlsthe amount the work may be pressed by the plunger in the direction ofthe path of the-needle. Thus, the crown controls the depth. ofpenetration.

In the operation of the sewing machine in felling a, lining to a coatfor example, the nodeformer l is adjusted to a single thickness of thecoat. The light spring Hi acting upon the plunger will be sufficient toeffect a node in the single thickness of material, and present thematerial to the needle, the depth of penetration bein controlled, ofcourse, by the adjustment of the crown. The machine is now operated, theoperator sewing up to the crossing of the pockets; the light plungerspring under the workpresenting plunger will yield and will not crushthe material. The operator continues to sew until the pocket flap isreached. At the pocket flap the work-presenting plunger will not comeup,

under the force of the light spring, sufficiently for the needle topenetrate the material. Then the gap between the automatic controlplunger 11 and the extension H of the work presenting plunger 1 isadjusted by turning the nut 21 until the needle penetrates the first plyof the material. The machine is now ready to sew across the pockets,and, if the adjustment has been made correctly, the machine will sew thelining to the coat, for there is ufiicient pressure applied by the heavyspring 22 acting on the lower control plunger H to force the materialupwardly into the opening of the presser foot so that the needle willpenetrate the desired amount. When the pocket flap is passed, then thespring 14 alone acts upon the work with a light enough pressure so thatit does not compress or crush the material hard enough for the needle tocatch through the pocket. When the machine is once adjusted in thismanner for varying thicknesses of cloth, no further adjustment for thework is required. For example, with the machine, adjusted as abovedescribed, the operation will be repeated as described above, withoutfurther adjustment, when another pocket flap is reached.

From the foregoing description of the embodiment of the inventionillustrated in the drawing, it will be seen that by this invention thereis provided a work-presenting mechanism for blindstitch sewing machinesthat includes a yieldable mounting for the node-former and in whichyieldable mounting there are two yieldable elements of difierentstrength arranged to act successively upon the node-former and in whichthe travel of the node-former towards the path of the needel isdecreased in accordance with the effectiveness of additional thicknessof material passing over the node-former.

It will be obvious that various changes may be made by those skilled inthe art in the details of the embodiment of the invention illustrated inthe drawing and described in detail above within the principle and scopeof the invention as expressed in the appended claims.

I claim;

1. In a blind-stitch sewing machine having stitch-forming mechanismincluding a needle, means for actuating the needle and means foractuating work-presenting mechanism in timed relation with the needle;work-presenting mechanism comprising in combination a node-formerarranged to project the work toward the path of the needle and mountedfor movement toward and away from the path of the needle, yieldablemeans normally acting upon the node-former for exerting a force thereonto position the nodeformer with respect to the path of the needle, andnormally ineffective yieldable means for exerting an additional force onthe node-former upon the yielding of said first-mentioned yieldablemeans.

2. In a blind-stitch sewing machine having stitch-forming mechanismincluding a needle, means for actuating the needle and means foractuating work-presenting mechanism in timed relation with the needle;work-presenting mechanism comprising in combination a mounting for anode-former, a node-former slidable in the node-former mounting andarranged to project the work into the path of the needle, yieldablemeans normally acting upon the node-former for exerting a force thereonto position the nodeformer with respect to the path of th needle, andadditional normally ineffective yieldable means for exerting anadditional force on the node-former upon the yielding of said normallyacting yieldable means, the several yieldable means exerting forces ofdifferent strengths- 3. In a blind-stitch sewing machine havingstitch-forming mechanism including a needle, means for actuatin theneedle and means for actuating work-presenting mechanism in timedrelation with the needle; work-presenting mechanism comprising incombination a node-former arranged to project the work into the path ofthe needle and mounted for movement toward and away from the path of theneedle, and a yieldable connection between the node-former and thework-presenting actuating mechanism of the sewing machine includingyieldable means normally acting upon the node-former for exerting aforce thereon to position the node-former with respect to the path ofthe needle, and normally ineffective yieldable means of a diiferentstrength than the normally effective yieldable means for exerting anadditional force on the node-former upon the yielding of saidfirst-mentioned yieldable means.

4. In a blind-stitch sewing machine having stitch-forming mechanismincluding a needle, means for actuating the needle and means foractuating work-presenting mechanism in timed.

relation with the needle; work-presenting mechanism comprising incombination a node-former arranged to project the work into the path ofthe needle and mounted for movement toward and away from the path of theneedle, a carrier for the node-former adapted to be actuated by thework-presenting actuating mechanism of the sewing machine, thenode-former being slidably mounted in said carrier, yieldable meansnormally acting upon the node-former for exerting a force thereon toposition the node-former with respect to the path of the needle, andnormally ineffective yieldable means for exerting an additional force onthe node-former upon the yielding of said first-mentioned yieldablemeans.

5. In a blind-stitch sewing machine having stitch-forming mechanismincluding a needle, means for actuating the needle and means foractuating work-presenting mechanism in timed relation with the needle;work-presenting mechanism comprising in combination a node-formerarranged to project the work into the path of the needle and mounted formovement toward and away from the path of the needle, a carrier for thenode-former adapted to be actuated by the work-presenting actuatingmeans of the sewing machine, the node-former being slidably mounted insaid carrier, yieldable means mounted on said carrier and normallyacting upon the node-former for exerting a force thereon to position thenode-former with respect to the path of the needle, and normallyinefiective yieldable means mounted on the carrier for exerting anadditional force on the node-former upon the yielding of saidfirst-mentioned yieldable means.

6. In a blind-stitch sewing machine having stitch-forming mechanismincluding a needle, means for actuating the needle and means foractuating work-presenting mechanism in timed relation with the needle;work-presenting mechanism comprising in combination a node-formerarranged to project the work into the path of the needle and mounted formovement toward and away from the path of the needle, means forconnecting said node-former for actuation by the work-presentingactuating mechanism of the sewing machine, a yieldable connectionbetween said connecting means and the nodeformer including yieldablemeans normally acting upon the node-former and for exerting a forcethereon to position'the node-former with respect to the path of theneedle and normally ineffective yieldable means for exerting anadditional force on the node-former upon the yielding of saidfirst-mentioned yieldable means, and means for adjusting the force ofsaid normally inefiective yieldable means.

7. In a blind-stitch sewing machine having stitch-forming mechanismincluding a needle, means for actuating the needle and means foractuating work-presenting mechanism in timed relation with the needle;work-presenting mechanism comprising in combination a node-formerarranged to project the work into the path of the needle and mounted formovement toward and away from the path of the needle, means forconnecting said node-former for actuation by the work-presentingactuating mechanism of the sewing machine, a yieldable connectionbetween said connecting means and the node-former and for exerting aforce thereon to position the nodeformer with respect to the path of theneedle and normally ineffective yieldable means for exerting anadditional force on the node-former upon the yielding of saidfirst-mentioned yieldable means, and means for adjusting the relation ofsaid normally ineffective yieldable means to the nodeformer.

8. In a blind-stitch sewing machine having stitch-forming mechanismincluding a needle, means for actuating the needle and means foractuating work-presenting mechanism in timed relation with the needle;work-presenting mechanism comprising in combination a node-formerarranged to project the work into the path of the needle and mounted formovement toward and away from the path of the needle, means forconnecting said node-former for actuation by the work-presentingactuating mechanism of the sewing machine, a yieldable connectionbetween said connecting means and the node-former including yieldablemeans normally acting upon the node-former and for exerting a forcethereon to position the node-former with respect to the path of theneedle and normally ineffective yieldable means for exerting anadditional force on the node-former upon the yielding of saidfirstmentioned yieldable means, means for adjusting the force of saidnormally ineffective yieldable means, and means for adjusting therelation of said normally ineffective yieldable means to thenode-former.

9. In a blind-stitch sewing machine having stitch-forming mechanismincluding a needle, means for actuating the needle and means foractuating work-presenting mechanism in timed relation with the needle;work-presenting niech anism comprising in combination a carrier adaptedto be actuated by the work-presenting actuating means of the sewingmachine, a nodeformer slidably mounted in the carrier, yieldable meansacting on said node-former in a direction to urge the node-former towardthe path of the needle; normally inefiective yieldable means behind andin line with but normally out of contact with the node-former forexerting an additional force on the node-former upon the yielding ofsaid first-mentioned means, means for adjusting the force of saidnormally inefiective yieldable means, and means for adjusting therelation of said normally ineffective yieldable means with respect tothe node-former.

10. In a blind-stitch sewing machine having stitch-forming mechanismincluding a needle, means for actuating the needle and means foractuating Work-presenting mechanism in timed relation with the needle;Work-presenting mechanism comprising in combination, a node-formerarranged to project the work into the path of the needle and mounted formovement toward and away from the path of the needle, and a yieldablemounting for the node-former including yieldable means normally actingupon the node-former for exerting a force thereon to position thenode-former with respect to the path of the needle, normally ineffectiveyieldable means for exerting an additional force on the nodeformer uponthe yielding of said first-mentioned yieldable means, and means arrangedin the path of the node-former for controlling the extent of theprojection of the work by the node-former.

11 In a blind-stitch sewing machine having stitch-forming mechanismincluding a needle, means for actuating the needle and means foractuating Work-presenting mechanism in timed relation with the needle;work-presenting mechanism comprising in combination, a node-formerarranged to project the work into the path of the needle and mounted formovement toward and away from the path of the needle, and a yieldablemounting for the node-former including yieldable means normally actingupon the node-former for exerting a force thereon to position thenode-former with respect to the path of the needle, normally ineffectiveyieldable means for exerting an additional force on the nodeformer uponthe yielding of said first-mentioned yieldable means, and meansincluding a rigid crown arranged in the path of the node-former forcontrolling the extent of the projection of the work by the node-former.

12, In a blind-stitch sewing machine having stitch-forming mechanismincluding a needle, means for actuating the needle and means foractuating work-presenting mechanism in timed relation with the needle;work-presenting mechanism comprising in combination, a node-formerarranged to project the work into the path of the needle and mounted formovement toward and away from the path of the needle, and a yieldablemounting for the node-former including yieldable means normally actingupon the node-former for exerting a force thereon to position thenodeformer with respect to the path of the needle, normally ineffectiveyieldable means for exerting an additional force on the node-former uponthe yielding of said first-mentioned yieldable means, and meansincluding a rigid, adjustable crown arranged in the path of thenode-former for controlling the extent of the projection of the Work bythe node-former.

CHARLES W. MUELLER.

